Young Americans are the linchpin of a new progressive era in American politics. So why aren't Democrats paying more attention to them?

The relative strength of conservatives in American politics since the 1980s was built on generational change: Voters whose views had been shaped by the New Deal were gradually replaced with the more cautious souls who came of age after FDR.

Then the Millennial generation came along. The Millennials--generally defined as Americans born in 1981 or after--are, without question, the most liberal generation since those New Dealers, and they could transform our politics for decades. But this will happen only if progressive politicians start noticing their very best friends in the electorate.

Progressives who doubt this could usefully spend time with the Pew Research Center's exhaustive new portrait of the Millennials that was released Wednesday. The study underscored the new generation's "distinctiveness," and a big part of that distinctiveness is how progressive younger Americans are compared with the rest of the country.

For one thing, they are not allergic to the word "liberal." Americans under thirty include the largest proportion of self-described liberals and the smallest proportion of self-described conservatives of any age group in the country: 29 percent of the under-thirties called themselves liberal compared with 28 percent who called themselves conservative.

"In every other age group," Pew notes, "far more described their views as conservative than liberal."

Among Gen Xers (born between 1965 and 1980), the conservative advantage over liberals was 38 percent to 20 percent. Among Baby Boomers (born 1946 to 1964), conservatives led 43 percent to 18 percent. Among those born in 1945 or before--Pew uses the classic "Silent Generation" tag--the conservative advantage was 45 percent to 15 percent. (Moderates and a few respondents who refused a label made up the remainder in all groups.)

The difference in self-labeling reflects real differences in attitudes. It's well-known that younger voters are more liberal on social issues, particularly gay rights. But their liberalism also includes sympathy for activist government.

For example, 53 percent of Millennials said that "government should do more to solve problems." In every other age group, pluralities preferred the alternative statement offered by the pollsters, that "government is doing too many things better left to business and individuals."

"Millennials," the report concludes, "are significantly less critical of government on a number of dimensions than are other age cohorts."

Important demographic factors account for some but not all of the distinctiveness of the new generation: Census data cited by Pew shows that 61 percent of the Millennials are white compared with 70 percent of Americans ages 30 and over. This means that political outreach to the young will require particular attention to Hispanics (19 percent of Millennials) and African Americans (14 percent).

For Democrats looking ahead to this fall's election, the Pew study has some disturbing news.

It's true that Millennials are the most Democratic age group in the electorate--they voted for Barack Obama by 2 to 1. Their turnout rate relative to older voters was higher in 2008 than in any election since 1972, the first presidential contest in which eighteen-year-olds had the right to vote.

But Pew notes that since 2008, the Millennials' "enthusiasms" have "cooled"--"for Obama and his message of change, for the Democratic Party and, quite possibly, for politics itself." 

Obama's personal ratings among the Millennials remain very high--three-fourths have a favorable view of the president--but his job approval rating has slipped from 73 percent a year ago to 57 percent this month. In the early months of last year, Democrats had a 29-point Millennial advantage over the Republicans. By the end of the year, their lead had been cut to 14 points.

That still keeps the eighteen-to-twenty-nine-year-olds the electorate's most Democratic age group. But Democrats face disaster this fall and real problems in 2012 if the Millennials become disaffected from politics, and if the Republicans continue to erode the Democrats' generational edge.

And what will Democrats do about it? Politicians have a bad habit in midterm elections: They concentrate on older folks, assuming younger voters will stay home on Election Day. 

This may be rational most of the time, but it is a foolish bet for Democrats and liberals this year. The young helped them rise to power and can just as easily usher them to early retirements. Obama cannot afford to break their hearts.

(c) 2010, Washington Post Writers Group